In semiconductor devices, various input/output lines (IO lines) may be used to read data from a memory cell or write data to a memory cell. Since a pair of IO lines may have different voltage levels after an IO line performs a write command or a read command, the IO line may be precharged before performing a next command.
An IO line of a semiconductor device may include a first IO line coupled to a bit line coupled to a memory cell via a column select circuit, and a second IO line coupled to the first IO line via a switch circuit. Here, the first IO line may be called a “local input/output line (LIO),” and the second IO line may be called a “global input/output line (GIO).”
Both the LIO and the GIO may be precharged after performing a first command and before performing a next command. Here, a precharge circuit of the GIO may be positioned at a peripheral region of a memory device and may precharge the GIO to a predetermined level between two commands.
As the density of a memory array increases, however, the distance between a peripheral region and a memory array region may also increase. If the distance is too great, a precharge circuit in the peripheral region may be unable to charge the GIO with sufficient speed. Thus, the precharge circuit of the GIO, positioned at the peripheral region, may not precharge or equalize the GIO in a given period of time.
In addition, while the density of a memory array increases, the operating speed of a memory device may also increase. Therefore, the precharge circuit of the GIO, positioned at the peripheral region, may not be able to precharge the IO line in a given period of time allowed at a higher operating speed.
If the IO line is not precharged in a given period of time allowed for a particular specification, operation errors may occur when data is written to or read from a memory. For this reason, a precharge circuit may be needed that can precisely precharge data IO lines at a high speed. Accordingly, a semiconductor device with a layout that can reduce the precharge time of GIOs may be desired.